Hide drop down if no items found

[Duncan]

Is there a way to hide the drop down of the RadCombo box if no items are found during the search?

Thanks,
Duncan

[Richard]

Duncan:

This topic is covered in-depth in the following forum thread:

How to disable dropdown when not databound?

Cheers!

[Duncan]

I'm sorry but that solution does not seem to work for me...

<telerik:RadScriptBlock ID="RadScriptBlock1" runat="server">
    <script type="text/javascript">
        function OnClientDropDownOpening(sender, eventArgs) {
            var combo = $find("<%= cboTags.ClientID %>");
            items = combo.get_items();
            if (items.get_count() == 0) {
                eventArgs.set_cancel(true);
            }
        }
    </script>
</telerik:RadScriptBlock>

<telerik:RadComboBox ID="cboTags" runat="server" CssClass="combo" AutoPostBack="true"
    Width="394px" EnableEmbeddedBaseStylesheet="False" EnableEmbeddedSkins="False"
    EnableTheming="False" ItemsPerRequest="8" MarkFirstMatch="True" ShowMoreResultsBox="True"
    ShowToggleImage="False" EmptyMessage="Tag Name" DropDownCssClass="combo-input-drop"
    Filter="Contains" DropDownWidth="410" EnableAutomaticLoadOnDemand="False" EnableLoadOnDemand="True"
    OffsetX="-38" OffsetY="-3" ShowDropDownOnTextboxClick="False" DataTextField="Tag"
    DataValueField="TagId" EnableTextSelection="False" NoWrap="True" AllowCustomText="True"
    Height="208" OnItemsRequested="cboTags_ItemsRequested" ValidationGroup="Form"
    OnClientItemsRequested="OnClientDropDownOpening">
</telerik:RadComboBox>

[Richard]

Duncan:

Can you post your .aspx markup and code behind so that we can better understand your scenario?

Regards,

[Duncan]

<%@ Page Title="" Language="C#" MasterPageFile="~/App_Master/Application.master"
    AutoEventWireup="true" CodeFile="Manage.aspx.cs" Inherits="Admin_Tags_Manage" %>

<asp:Content ID="Content1" ContentPlaceHolderID="ph_head" runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ph_content" runat="Server">
    <telerik:RadScriptBlock ID="RadScriptBlock1" runat="server">
        <script type="text/javascript">
            function OnClientDropDownOpening(sender, eventArgs) {
                var combo = $find("<%= cboTags.ClientID %>");
                items = combo.get_items();
                if (items.get_count() == 0) {
                    eventArgs.set_cancel(true);
                }
            }
        </script>
    </telerik:RadScriptBlock>
    <telerik:RadAjaxLoadingPanel ID="loadingpanelFull" runat="server" Skin="" Transparency="30"
        CssClass="loading">
        <div class="full">
        </div>
    </telerik:RadAjaxLoadingPanel>
    <telerik:RadAjaxPanel ID="radAjaxPanel" runat="server" LoadingPanelID="loadingpanelFull">
        <asp:Panel ID="pnlOverlay" runat="server" Visible="false">
            <div class="sample_data_overlay">
                 </div>
            <div class="sample_data_popup">
                <h4>
                    <asp:Label ID="lblPopupHeader" runat="server" />
                </h4>
                <p>
                    <asp:Label ID="lblPopupText" runat="server" /></p>
                <asp:Panel ID="pnlActionButton" runat="server">
                    <asp:HyperLink ID="lnkPopupAction" runat="server" />
                </asp:Panel>
            </div>
        </asp:Panel>
        <asp:Repeater ID="rptChoicesMenu" runat="server" OnItemCommand="ChoicesMenu_ItemCommand"
            OnItemDataBound="ChoicesMenu_ItemDataBound">
            <HeaderTemplate>
                <ul class="contentchoices">
            </HeaderTemplate>
            <ItemTemplate>
                <li id="ListItem" runat="server">
                    <asp:LinkButton ID="btnItem" runat="server" /></li>
            </ItemTemplate>
            <FooterTemplate>
                </ul></FooterTemplate>
        </asp:Repeater>
        <asp:Panel ID="pnlEditOverlay" runat="server" Visible="false">
            <div class="sample_data_overlay">
                 </div>
            <div class="sample_data_popup">
                <h4>
                    Edit This Tag:</h4>
                <p>
                    Please edit the tag and its related tags below.</p>
                <table border="0" cellspacing="0" cellpadding="0" class="editform">
                    <tr>
                        <td>
                            <telerik:RadTextBox ID="txtTag" runat="server" class="textbox" EnableEmbeddedBaseStylesheet="False"
                                EnableEmbeddedSkins="False" EnableTheming="False" EmptyMessage="Tag Name" />
                        </td>
                    </tr>
                    <tr>
                        <th>
                            Add/Remove Related Tags:
                        </th>
                    </tr>
                    <tr>
                        <td>
                            <div class="withbutton">
                                <asp:HiddenField ID="hdnCurrentTagId" runat="server" />
                                <telerik:RadComboBox ID="cboTags" runat="server" CssClass="combo" AutoPostBack="true"
                                    Width="394px" EnableEmbeddedBaseStylesheet="False" EnableEmbeddedSkins="False"
                                    EnableTheming="False" ItemsPerRequest="8" MarkFirstMatch="True" ShowMoreResultsBox="True"
                                    ShowToggleImage="False" EmptyMessage="Tag Name" DropDownCssClass="combo-input-drop"
                                    Filter="Contains" DropDownWidth="410" EnableAutomaticLoadOnDemand="False" EnableLoadOnDemand="True"
                                    OffsetX="-38" OffsetY="-3" ShowDropDownOnTextboxClick="False" DataTextField="Tag"
                                    DataValueField="TagId" EnableTextSelection="False" NoWrap="True" AllowCustomText="True"
                                    Height="208" OnItemsRequested="cboTags_ItemsRequested" ValidationGroup="Form"
                                    OnClientItemsRequested="OnClientDropDownOpening">
                                </telerik:RadComboBox>
                            </div>
                            <div class="add">
                                <asp:LinkButton ID="btnAdd" runat="server" OnClick="btnAdd_Click" ValidationGroup="Form" />
                            </div>
                        </td>
                    </tr>
                    <asp:Repeater ID="rptRelatedTags" runat="server" OnItemCommand="Tags_ItemCommand"
                        OnItemDataBound="Tags_ItemDataBound">
                        <ItemTemplate>
                            <tr>
                                <td class="urlcell">
                                    <div class="withbutton">
                                        <asp:LinkButton ID="btnTag" runat="server" CommandName="edit" CausesValidation="False" /></div>
                                    <div class="remove">
                                        <asp:LinkButton ID="btnRemove" runat="server" CommandName="remove" CausesValidation="False" /></div>
                                </td>
                            </tr>
                        </ItemTemplate>
                    </asp:Repeater>
                    <tr>
                        <th>
                            Other Tags Relating:
                        </th>
                    </tr>
                    <asp:Repeater ID="rptRelatingTags" runat="server" OnItemCommand="Tags_ItemCommand"
                        OnItemDataBound="Tags_ItemDataBound">
                        <ItemTemplate>
                            <tr>
                                <td class="urlcell">
                                    <div class="withbutton">
                                        <asp:LinkButton ID="btnTag" runat="server" CommandName="edit" CausesValidation="False" /></div>
                                    <div class="add">
                                        <asp:LinkButton ID="btnAdd" runat="server" CommandName="add" CausesValidation="False" /></div>
                                </td>
                            </tr>
                        </ItemTemplate>
                    </asp:Repeater>
                </table>
                <asp:Panel ID="pnlSaveButton" runat="server">
                    <asp:LinkButton ID="btnSave" runat="server" OnClick="btnSave_Click" />
                </asp:Panel>
                <div class="cancel">
                    <asp:LinkButton ID="btnCancel" runat="server" Text="Cancel" OnClick="btnCancel_Click" /></div>
            </div>
        </asp:Panel>
        <div class="clearfloat">
        </div>
        <h1>
            New Tags Added</h1>
        <div class="stat-fullgraph">
            <div class="graph">
                <asp:Image ID="imgTagsAdded" runat="server" /></div>
        </div>
        <div class="clearfloat">
        </div>
        <h1>
            Manage Tags</h1>
        <div class="clearfloat">
        </div>
        <table border="0" cellspacing="0" cellpadding="0" class="datatable">
            <tr>
                <td>
                    <div class="header">
                        <div class="text">
                            The selected tags have related tags</div>
                    </div>
                </td>
            </tr>
            <tr>
                <td class="typerow">
                    Tags:
                </td>
            </tr>
            <asp:Repeater ID="rptItems" runat="server" OnItemDataBound="rptItems_ItemDataBound"
                OnItemCommand="rtpItems_ItemCommand">
                <ItemTemplate>
                    <tr>
                        <td>
                            <table border="0" cellspacing="0" cellpadding="0">
                                <tr class="trhover">
                                    <td class="checkcol">
                                        <asp:CheckBox ID="chkHasRelated" runat="server" AutoPostBack="True" Enabled="false" />
                                    </td>
                                    <td class="admin-itemcol">
                                        <div>
                                            <asp:LinkButton ID="btnItemName" CommandName="edit" runat="server" />  <asp:Label
                                                ID="lblProfileFullName" runat="server" /></div>
                                    </td>
                                    <td class="admin-approvecol">
                                        <asp:LinkButton ID="btnApprove" runat="server" CommandName="approve" Text="Approve" />
                                    </td>
                                    <td class="admin-removecol">
                                        <asp:LinkButton ID="btnRemove" runat="server" CommandName="remove" Text="Remove" />
                                    </td>
                                </tr>
                            </table>
                        </td>
                    </tr>
                </ItemTemplate>
            </asp:Repeater>
        </table>
    </telerik:RadAjaxPanel>
</asp:Content>

The relevant parts of the code behind are:

protected void cboTags_ItemsRequested(object sender, Telerik.Web.UI.RadComboBoxItemsRequestedEventArgs e)
{
    Tags_DataBind();
}

public void Tags_DataBind()
{
    TagsBL tagsbl = new TagsBL(conn);

    cboTags.DataSource = tagsbl.GetAllTags(contextuser);
    cboTags.DataBind();
    cboTags.SortItems();
}

[Richard]

Duncan:

Why not simply check to see if your RadComboBox.Item.Count == 0 after binding it, and if so, set RadComboBox.Enabled = false.

This simple mock up worked for me when the XML source file contains no items:

using Telerik.Web.UI;

public partial class Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            RadComboBox1.LoadContentFile("combobox2.xml");

            if (RadComboBox1.Items.Count == 0)
            {
                RadComboBox1.Enabled = false;
            }
        }

    }
}

Hope this helps!

[Duncan]

I'm not sure that would work with EnableLoadOnDemand set to true as there are always items being bound but not always being shown... if that makes sense...